Check that capitalized 'Append' works for ChainInsertMode
Check that capitalized 'Append' works for ChainInsertMode

(In relation to https://github.com/projectcalico/calico/pull/1968)

neiljerram/felix,neiljerram/felix,Metaswitch/calico,Metaswitch/calico,neiljerram/felix,neiljerram/felix